Since deciding to leave the Mercedes camp and switch to Honda, McLaren supremo Ron Dennis has frequently said success in formula one is only possible today in works collaboration with a manufacturer or "OEM".

In 2014 and again this year, independent British outfit Williams has been Mercedes' most competitive customer of its field-leading turbo V6 'power unit'.

But Valtteri Bottas and Felipe Massa have not won a race in that period for the Grove team, and technical boss Symonds admits the works Mercedes outfit as well as Ferrari are clearly in the lead this season.

"Are we in that position (to win races)?" he said recently. "No, we are not."

But Symonds rejects Dennis' notion that winning as an engine customer in the new era of F1 is impossible.

"I don't think being an engine customer is the end of the world," the veteran engineer, who has won titles at Renault but also worked at the back of the grid with Marussia, told UOL Esporte.

"Everybody started to talk about it because of what Ron Dennis said. But when people like me talk to people like you (journalists), we do it for a reason.

"It is not to entertain ourselves, it is because we want to give some exposure to our team or because we want to give our opinion.

"And I think Ron wanted to clarify his point of view, or explain why he had chosen to be with Honda -- to convince his sponsors that this is the only way to win," said Symonds.

Symonds, however, said Dennis' logic is flawed.

"He forgets that in 2009, McLaren was the main Mercedes team and they were beaten by Brawn, who were the customer. So it's something that can be done -- and why can't we do the same?" he insisted.

Symonds says Williams' contract with Mercedes ensures technical parity, and hailed the customer service provided by the German marque.

"They work with us all of the time," he said, "during the race weekends, in our performance meetings and doing things like video conferencing when necessary.

"They are contracted to work for Williams, so it is in their interest not only that Mercedes wins, but that Williams-Mercedes can win as well," added Symonds.